1. Technical Field
The present invention relates to chip dicing, and more particularly, to a chip separation method using a laser.
2. Related Art
Chip dicing is the process of separating individual chips from a wafer. Typically, chip dicing involves the use of a saw blade, chemicals, a laser, or their combination to cut through and along kerf regions (dicing channels) that run between the chips of the wafer.
A saw blade can cut through the dicing channels at a high speed. However, because each of the dicing channels must be wider than the width of the saw blade (which is typically 100 μm), a large wafer area must be used for chip dicing, which is undesirable.
The dicing channels usually comprise test circuits used to test the functionality of the chips. If chemicals are used to etch through the dicing channels, different chemicals and steps must be used to etch through different materials of the test circuits which reside in the dicing channels. As a result, the dicing process becomes time consuming and expensive.
A laser can make a narrower cut (typically 10 μm wide) through the dicing channels than a saw blade. However, the cutting speed of the laser is usually slow compared to the cutting speed of a saw blade.
In short, each of the cutting means for chip dicing described above has advantages and disadvantages. Therefore, there is a need for a novel structure and chip dicing method that uses an optimum combination of these cutting means for chip dicing.